Theorising the use of private military and security companies: a synthetic perspective

This article seeks to systematise and advance the theoretical debate on the causes and conditions for the privatisation of security. Drawing on previous research on private military and security companies (PMSCs) and theories from International Relations and Comparative Politics, it reconstructs functionalist, political-instrumentalist and ideationist explanations for why and under what conditions even ‘strong’ and democratic Organisation for Economic Co-operation and Development states (extensively) use PMSCs. An analysis of inter-temporal and cross-national (United States, British, German and French) patterns of security privatisation indicates that all the three theoretical models point out causes and conditions that are relevant for a comprehensive explanation, but none is sufficient alone. Therefore, the article uses both the models and the empirical evidence to propose a synthetic perspective, which treats different explanatory conditions and logics as complementary, rather than rival. Going beyond the atheoretical conclusion that a multitude of disconnected factors are in some way relevant for a comprehensive explanation of security privatisation, I develop a thin and a thick synthesis that rely on a domain-of-application approach and sequencing, respectively. The thin synthesis spells out how different explanatory factors operate in specific domains, whereas the thick synthesis elaborates how different conditions and mechanisms apply to different phases of security privatisation and how they interrelate.